Avengers (1963 1st Series) #300

"Inferno 2" Inferno crossover. Giant-Sized Anniversary Issue. Script by Walt Simonson. Art by John Buscema (layouts) and Tom Palmer (finishes). Cover by John Buscema and Tom Palmer.

It's the tricentennial issue of Earth's Mightiest Heroes! And the all-out action begins in Central Park as Nanny places Franklin Richards in a red suit of armor and orders him to attack his parents!